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Articles 1 - 30 of 119

Full-Text Articles in Social and Behavioral Sciences

Triboelectric Nanogenerator Versus Piezoelectric Generator At Low Frequency (<4 Hz): A Quantitative Comparison, Abdelsalam Ahmed, Islam Hassan, Ahmed Helal, Vitor Sencadas, Ali Radhi, Chang Jeong, Maher El-Kady Jan 2020

Triboelectric Nanogenerator Versus Piezoelectric Generator At Low Frequency (<4 Hz): A Quantitative Comparison, Abdelsalam Ahmed, Islam Hassan, Ahmed Helal, Vitor Sencadas, Ali Radhi, Chang Jeong, Maher El-Kady

Faculty of Engineering and Information Sciences - Papers: Part B

© 2020 The Author(s) Triboelectric nanogenerators (TENGs) and piezoelectric generators (PGs) are generally considered the two most common approaches for harvesting ambient mechanical energy that is ubiquitous in our everyday life. The main difference between the two generators lies in their respective working frequency range. Despite the remarkable progress, there has been no quantitative studies on the operating frequency band of the two generators at frequency values below 4 Hz, typical of human motion. Here, the two generators are systematically compared based on their energy harvesting capabilities below 4 Hz. Unlike PGs, the TENG demonstrates higher power performance and is …


Air Void Detection Using Variational Mode Decomposition With Low Rank, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Shivakumar Karekal Jan 2020

Air Void Detection Using Variational Mode Decomposition With Low Rank, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Shivakumar Karekal

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents an air-void detection technique for air-coupled radar, which emits electromagnetic waves to interrogate an air-void inside a medium or between two media. The reflections from the air-medium interfaces are usually corrupted by air-coupling, antenna ringing, and internal reflections, rendering air-void detection very difficult or, in certain cases, impossible. The proposed method exploits the low-rank structure of the background clutter to suppress these nuisance signals. A variational mode decomposition model is developed to extract the backscattering at different air-medium interfaces as signal modes. Real experiments are conducted using a stepped frequency radar. The experimental results show that the …


Low Levels Of After School-Hours Social Interaction And Physical Activity Of 5-7 Year Olds, Anita C. Bundy, Lina Engelen, Geraldine A. Naughton, Shirley Wyver Jan 2018

Low Levels Of After School-Hours Social Interaction And Physical Activity Of 5-7 Year Olds, Anita C. Bundy, Lina Engelen, Geraldine A. Naughton, Shirley Wyver

Faculty of Social Sciences - Papers (Archive)

As part of a cluster randomized controlled trial (Bundy et al., 2017), the after school-hours activities of 5-7 year old children were recorded by parents and other adult carers on four consecutive weekdays between 3:30pm-7:00pm. Records of time use showed most time was spent indoors in activities involving low levels of physical activity. The most-frequently-recorded activity was screen time, accounting for approximately one quarter of all activities. Higher levels of physical activity were reported when children were outdoors (19.5% of time) and/or with peers (9.58%). If an adult was present, highest activity levels of children occurred when the child was …


Parsimonious Network Based On A Fuzzy Inference System (Panfis) For Time Series Feature Prediction Of Low Speed Slew Bearing Prognosis, Wahyu Caesarendra, Mahardhika Pratama, Buyung Kosasih, Tegoeh Tjahjowidodo, Adam Glowacz Jan 2018

Parsimonious Network Based On A Fuzzy Inference System (Panfis) For Time Series Feature Prediction Of Low Speed Slew Bearing Prognosis, Wahyu Caesarendra, Mahardhika Pratama, Buyung Kosasih, Tegoeh Tjahjowidodo, Adam Glowacz

Faculty of Engineering and Information Sciences - Papers: Part B

In recent years, the utilization of rotating parts, e.g., bearings and gears, has been continuously supporting the manufacturing line to produce a consistent output quality. Due to their critical role, the breakdown of these components might significantly impact the production rate. Prognosis, which is an approach that predicts the machine failure, has attracted significant interest in the last few decades. In this paper, the prognostic approaches are described briefly and advanced predictive analytics, namely a parsimonious network based on a fuzzy inference system (PANFIS), is proposed and tested for low speed slew bearing data. PANFIS differs itself from conventional prognostic …


Relationship Between Socioeconomic Status And High School Dropout Retention Plans, Nicholas Sciancalepore Jun 2017

Relationship Between Socioeconomic Status And High School Dropout Retention Plans, Nicholas Sciancalepore

Theses and Dissertations

Different areas in the United States have varying levels of economic hardships. The United States Department of Education states that 4.7% of ninth graders in low socioeconomic areas drop out of school. This means that they may not receive an education strong enough to get a job that can sustain them. We aimed to find out which schools have lower dropout rates as compared to the average we can focus on what these schools are doing correctly as compared to ones where the dropout rate is higher. This study looks at data compiled from 57 schools that teach at least …


A Workshop In Creative Problem Solving Skills To Enhance Resilience In Low-Socioeconomic Status Black Males, Najja A. Bouldin Apr 2017

A Workshop In Creative Problem Solving Skills To Enhance Resilience In Low-Socioeconomic Status Black Males, Najja A. Bouldin

Creativity and Change Leadership Graduate Student Master's Projects

Abstract

Creative problem solving skills are an important tool in many areas of life. This project is a written account of what a workshop and coaching methods for Black males of low socio-economic status (SES) who attend an intensive creative problem solving skill-strengthening boot camp to enhance resiliency looks like in real time. This a workshop of creative problem solving skills and resilience enhancement, a intensive intervention based on Creative Resilience work and low socio-economic Black males’ engagement in this CPS by increasing awareness of the need to change and/or enhance creativity and resilience. Participants in a six module, group, …


Let's Address Low Visual Arts Self-Efficacy, Gai M. Lindsay Jan 2017

Let's Address Low Visual Arts Self-Efficacy, Gai M. Lindsay

Faculty of Social Sciences - Papers (Archive)

Visual arts pedagogy and the place of visual arts in the curriculum are determined by the collision of teachers' visual arts self-efficacy beliefs, pedagogical beliefs about children's learning processes and visual arts content knowledge.


Integrated Condition Monitoring And Prognosis Method For Incipient Defect Detection And Remaining Life Prediction Of Low Speed Slew Bearings, Wahyu Caesarendra, Tegoeh Tjahjowidodo, Buyung Kosasih, Anh Kiet Tieu Jan 2017

Integrated Condition Monitoring And Prognosis Method For Incipient Defect Detection And Remaining Life Prediction Of Low Speed Slew Bearings, Wahyu Caesarendra, Tegoeh Tjahjowidodo, Buyung Kosasih, Anh Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents an application of multivariate state estimation technique (MSET), sequential probability ratio test (SPRT) and kernel regression for low speed slew bearing condition monitoring and prognosis. The method is applied in two steps. Step (1) is the detection of the incipient slew bearing defect. In this step, combined MSET and SPRT is used with circular-domain kurtosis, time-domain kurtosis, wavelet decomposition (WD) kurtosis, empirical mode decomposition (EMD) kurtosis and the largest Lyapunov exponent (LLE) feature. Step (2) is the prediction of the selected features' trends and the estimation of the remaining useful life (RUL) of the slew bearing. In …


What Factors Contribute To The Continued Low Rates Of Indigenous Status Identification In Urban General Practice? - A Mixed-Methods Multiple Site Case Study, Heike Schutze, Lisa Jackson Pulver, Mark Fort Harris Jan 2017

What Factors Contribute To The Continued Low Rates Of Indigenous Status Identification In Urban General Practice? - A Mixed-Methods Multiple Site Case Study, Heike Schutze, Lisa Jackson Pulver, Mark Fort Harris

Faculty of Social Sciences - Papers (Archive)

Background Indigenous peoples experience worse health and die at younger ages than their non-indigenous counterparts. Ethnicity data enables health services to identify inequalities experienced by minority populations and to implement and monitor services specifically targeting them. Despite significant Government intervention, Australia's Indigenous peoples, the Aboriginal and Torres Strait Islander peoples, continue to be under identified in data sets. We explored the barriers to Indigenous status identification in urban general practice in two areas in Sydney. Methods A mixed-methods multiple-site case study was used, set in urban general practice. Data collection included semi-structured interviews and self-complete questionnaires with 31 general practice …


Relationship Between Indoor Air Temperatures And Energy Bills For Low Income Homes In Australia, Clayton Mcdowell, Georgios Kokogiannakis, Laia Ledo Gomis, Paul Cooper Jan 2017

Relationship Between Indoor Air Temperatures And Energy Bills For Low Income Homes In Australia, Clayton Mcdowell, Georgios Kokogiannakis, Laia Ledo Gomis, Paul Cooper

Faculty of Engineering and Information Sciences - Papers: Part B

Energy poverty is a prevalent issue in Australia and other countries across the globe especially for people with a low income. This paper seeks to investigate the relationship of energy consumption and indoor air temperatures and is separated into 3 sections; a comparison of actual electricity consumption to energy benchmarks provided by the Australian Energy Regulator, monitoring results of living room air temperature for the winter of 2015, and an analysis of living room air temperatures versus electricity consumption. The results of a comparison of electricity consumption of 119 low income elderly peoples (60+) dwellings to that of the energy …


The Psychology Of Romantic Relationships, Darby Dietrich Jun 2016

The Psychology Of Romantic Relationships, Darby Dietrich

Honors Theses

Prior research on self-monitoring suggests that high self-monitors are more likely to choose a romantic partner based on status and appearance. Conversely, low self-monitors put a greater emphasis on shared values and interests. In the current research, we examined the self-monitoring differences in both dating relationships and marriages. Participants were given a survey in which they answered personal questions, questions about their past relationships, qualities that are important in potential dating and marriage partners, and the Snyder and Gangestad (1986) 18-item Self-Monitoring scale. Trends were consistent with previous research, such that high self-monitors were more likely to divorce than low …


An Internet-Supported Physical Activity Intervention Delivered In Secondary Schools Located In Low Socio-Economic Status Communities: Study Protocol For The Activity And Motivation In Physical Education (Amped) Cluster Randomized Controlled Trial, Chris Lonsdale, Aidan Lester, Katherine B. Owen, Rhiannon L. White, Ian Moyes, Louisa Peralta, Morwenna Kirwan, Anthony Maeder, Andrew Bennie, Freya Macmillan, Gregory Kolt, Nikos Ntoumanis, Jennifer M. Gore, Ester Cerin, Thierno M.O Diallo, Dylan P. Cliff, David R. Lubans Jan 2016

An Internet-Supported Physical Activity Intervention Delivered In Secondary Schools Located In Low Socio-Economic Status Communities: Study Protocol For The Activity And Motivation In Physical Education (Amped) Cluster Randomized Controlled Trial, Chris Lonsdale, Aidan Lester, Katherine B. Owen, Rhiannon L. White, Ian Moyes, Louisa Peralta, Morwenna Kirwan, Anthony Maeder, Andrew Bennie, Freya Macmillan, Gregory Kolt, Nikos Ntoumanis, Jennifer M. Gore, Ester Cerin, Thierno M.O Diallo, Dylan P. Cliff, David R. Lubans

Faculty of Social Sciences - Papers (Archive)

Background: School-based physical education is an important public health initiative as it has the potential to provide students with regular opportunities to participate in moderate-to-vigorous physical activity (MVPA). Unfortunately, in many physical education lessons students do not engage in sufficient MVPA to achieve health benefits. In this trial we will test the efficacy of a teacher professional development intervention, delivered partially via the Internet, on secondary school students' MVPA during physical education lessons. Teaching strategies covered in this training are designed to (i) maximize opportunities for students to be physically active during lessons and (ii) enhance students' autonomous motivation towards …


Cognitive And Oculomotor Performance In Subjects With Low And High Schizotypy: Implications For Translational Drug Development Studies, Ivan Koychev, D Joyce, Emma Barkus, Ulrich Ettinger, Anne Schmechtig, Colin Dourish, Gerard Dawson, Kevin Craig, John Francis Deakin Jan 2016

Cognitive And Oculomotor Performance In Subjects With Low And High Schizotypy: Implications For Translational Drug Development Studies, Ivan Koychev, D Joyce, Emma Barkus, Ulrich Ettinger, Anne Schmechtig, Colin Dourish, Gerard Dawson, Kevin Craig, John Francis Deakin

Faculty of Social Sciences - Papers (Archive)

The development of drugs to improve cognition in patients with schizophrenia is a major unmet clinical need. A number of promising compounds failed in recent clinical trials, a pattern linked to poor translation between preclinical and clinical stages of drug development. Seeking proof of efficacy in early Phase 1 studies in surrogate patient populations (for example, high schizotypy individuals where subtle cognitive impairment is present) has been suggested as a strategy to reduce attrition in the later stages of drug development. However, there is little agreement regarding the pattern of distribution of schizotypal features in the general population, creating uncertainty …


Radar Imaging Of Stationary Indoor Targets Using Joint Low-Rank And Sparsity Constraints, Van Ha Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive Jan 2016

Radar Imaging Of Stationary Indoor Targets Using Joint Low-Rank And Sparsity Constraints, Van Ha Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive

Faculty of Engineering and Information Sciences - Papers: Part A

This paper introduces a joint low-rank and sparsity-based model to address the problem of wall-clutter mitigation in compressed through-the-wall radar imaging. The proposed model is motivated by two observations that wall reflections reside in a low-rank subspace, and target signals tend to be sparse. In the proposed approach, the task of segregating target returns from wall reflections is formulated as a joint low-rank and sparsity constrained optimization problem. Here, the low rank constraint is imposed on the wall component and the sparsity constraint is used to model the target component. An iterative soft thresholding algorithm is developed to estimate a …


Analysis Of Bacterial Diversity In Two Oil Blocks From Two Low-Permeability Reservoirs With High Salinities, Meng Xiao, Shan Shan Sun, Zhong Zhi Zhang, Junming Wang, Long Wei Qiu, Hua Yang Sun, Zhaozheng Song, Beiyu Zhang, De Li Gao, Guangqing Zhang, Wei Min Wu Jan 2016

Analysis Of Bacterial Diversity In Two Oil Blocks From Two Low-Permeability Reservoirs With High Salinities, Meng Xiao, Shan Shan Sun, Zhong Zhi Zhang, Junming Wang, Long Wei Qiu, Hua Yang Sun, Zhaozheng Song, Beiyu Zhang, De Li Gao, Guangqing Zhang, Wei Min Wu

Faculty of Engineering and Information Sciences - Papers: Part A

The community diversities of two oil reservoirs with low permeability of 1.81 x 10 '3 and 2.29 x 10 '3 1/4m 2 in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher …


Indoor Scene Reconstruction For Through-The-Wall Radar Imaging Using Low-Rank And Sparsity Constraints, Van H. Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive Jan 2016

Indoor Scene Reconstruction For Through-The-Wall Radar Imaging Using Low-Rank And Sparsity Constraints, Van H. Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive

Faculty of Engineering and Information Sciences - Papers: Part A

This paper addresses the problem of indoor scene reconstruction in compressed sensing through-the-wall radar imaging. The proposed method is motivated by two observations that wall reflections reside in a low-rank subspace and the imaged scene tends to be sparse. The task of mitigating the wall reflections and reconstructing an image of the scene behind-the-wall is cast as a joint low-rank and sparsity constrained optimization problem, where a low-rank matrix captures the wall returns and a sparse matrix represents the formed image. An iterative algorithm is developed to estimate the low-rank matrix and the sparse scene vector from a reduced measurement …


Transient Cfd Modelling Of Low-Temperature Spontaneous Heating Behaviour In Multiple Coal Stockpiles With Wind Forced Convection, Jian Zhang, Yuntao Liang, Ting X. Ren, Zhongwei Wang, Gongda Wang Jan 2016

Transient Cfd Modelling Of Low-Temperature Spontaneous Heating Behaviour In Multiple Coal Stockpiles With Wind Forced Convection, Jian Zhang, Yuntao Liang, Ting X. Ren, Zhongwei Wang, Gongda Wang

Faculty of Engineering and Information Sciences - Papers: Part A

Spontaneous heating of coal stockpile has long been a thermal dynamic hazard during coal storage, processing, and transport. A transient non-equilibrium thermal CFD model has been developed to study the low-temperature self-heating behaviour of coal in multiple stockpiles under different prevailing wind conditions. Modelling results from the initial steady wind flow simulation indicate that a wake region can be induced on the leeward side of each coal stockpile. Pressure coefficient drops when the wind stream encounters or leaves a stockpile and the pressure coefficient profiles of multiple stockpiles tend to have more resemblance with a wider spacing. The first stockpile …


Revisiting The Link Between Low Verbal Intelligence And Ideology, Peter Leeson, Patrick Heaven, Joseph Ciarrochi Jul 2015

Revisiting The Link Between Low Verbal Intelligence And Ideology, Peter Leeson, Patrick Heaven, Joseph Ciarrochi

joseph Ciarrochi

We address a series of criticisms, raised by Woodley (2011), of our paper “Cognitive ability, right-wing authoritarianism, and social dominance orientation: A five-year longitudinal study amongst adolescents” (Heaven, Ciarrochi, & Leeson, 2011). We argue that, while Woodley (2011) presents some interesting points, his criticisms do not alter our initial interpretation that verbal intelligence influences the individual's ideological perspective. We also argue that the use of RWA and SDO in our paper is not problematic given that these variables are treated as ideological constructs and not measures of personality. We further challenge the assumption that our reported relationship between low IQ …


Adolescents Who Need Help The Most Are The Least Likely To Seek It: The Realtionship Between Low Emotional Competence And Low Intention To Seek Help, Joseph Ciarrochi, Frank Deane, Coralie Wilson, Debra Rickwood Jul 2015

Adolescents Who Need Help The Most Are The Least Likely To Seek It: The Realtionship Between Low Emotional Competence And Low Intention To Seek Help, Joseph Ciarrochi, Frank Deane, Coralie Wilson, Debra Rickwood

joseph Ciarrochi

It has been found that university students who were the least skilled at managing their emotions also had the lowest intention of seeking help from a variety of nonprofessional sources (e.g. family and friends). The present study sought to extend these findings by focusing on adolescents, examining a larger number of emotional competencies, and exploring the possibility that social support explains the relationship between emotional competence and help-seeking. A total of 137 adolescents (aged 16-18) completed an anonymous survey that assessed social support, emotional competencies, and intention to seek help from a variety of professional and nonprofessional sources. As expected, …


Perceived Value Of Using Energy Efficiently Among Low-Income Older Residents, Katherine A. Butler, Ross Gordon, Katherine Roggeveen, Gordon R. Waitt, Paul Cooper Jan 2015

Perceived Value Of Using Energy Efficiently Among Low-Income Older Residents, Katherine A. Butler, Ross Gordon, Katherine Roggeveen, Gordon R. Waitt, Paul Cooper

Faculty of Social Sciences - Papers (Archive)

Abstract presented at the World Social Marketing Conference, 19-21 April 2015, Sydney, Australia


Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a simple methodology to improve the low voltage ride-through (LVRT) capability of Doubly Fed Induction Generator (DFIG) based wind turbines in order to ride through higher voltage sags and durations. The proposed method is based on selection of an appropriate value for DC side super capacitor (SC) in such a way that it could help wind turbine for LVRT without any need to crowbar protection. The operation of SC based wind turbine in normal and fault conditions is simulated using MATLAB/SIMULINK. The simulation results show that the proposed method can be used effectively for LVRT improvement and …


Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury Jan 2015

Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage dips are considered to be one of the costliest of all power quality disturbances due to their disruption of industrial and commercial operations. The ability to characterise the voltage dip performance of distribution networks has many benefits for industry. There is considerable potential for industry to make large economic gains if voltage dip behaviour can be better understood and planned for. To put strategies in place to deal with voltage dips, there is a need for extensive data collection and analysis so that correct planning decisions can be made. This study details the characteristics of voltage dip data which …


Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Fully converter wind turbines and solar power utilise an inverter to connect to grid. The inverters are vulnerable to voltage sag in their terminal due to its damaging effect on semiconductor self-Turnoff switches. In this paper, a bridge-Type fault current limiter (B-FCL) is proposed for low voltage ride-Through (LVRT) of the inverters during different types of fault with simple control system. The proposed B-FCL is capable to compensate the voltage sag in point of common coupling (PCC) and makes a safe condition not only for the inverter but also for any equipment which has been connected to the PCC in …


Interface Analysis And Hot Deformation Behaviour Of A Novel Laminated Composite With High-Cr Cast Iron And Low Carbon Steel Prepared By Hot Compression Bonding, Zhengyi Jiang, Xingjian Gao, Sheng-Li Li, Hong Mei Zhang, Dengfu Chen, Jian Zhong Xu Jan 2015

Interface Analysis And Hot Deformation Behaviour Of A Novel Laminated Composite With High-Cr Cast Iron And Low Carbon Steel Prepared By Hot Compression Bonding, Zhengyi Jiang, Xingjian Gao, Sheng-Li Li, Hong Mei Zhang, Dengfu Chen, Jian Zhong Xu

Faculty of Engineering and Information Sciences - Papers: Part A

A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron (HCCI) as the inner layer and low carbon steel (LCS) as the outer layers on a Gleeble 3500 thermomechanical simulator at a temperature of 950 °C and a strain rate of 0.001 S-1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by microstructural characterisation and mechanical tests. Experimental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer …


Application Of The Largest Lyapunov Exponent Algorithm For Feature Extraction In Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie Jan 2015

Application Of The Largest Lyapunov Exponent Algorithm For Feature Extraction In Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new application of the largest Lyapunov exponent (LLE) algorithm for feature extraction method in low speed slew bearing condition monitoring. The LLE algorithm is employed to measure the degree of non-linearity of the vibration signal which is not easily monitored by existing methods. The method is able to detect changes in the condition of the bearing and demonstrates better tracking of the progressive deterioration of the bearing during the 139 measurement days than comparable methods such as the time domain feature methods based on root mean square (RMS), skewness and kurtosis extraction from the raw vibration …


Comparative Evaluation Of Modern Dosimetry Techniques Near Low- And High-Density Heterogeneities, Eyad A. Alhakeem, Sami Alshaikh, Anatoly B. Rosenfeld, Sergei F. Zavgorodni Jan 2015

Comparative Evaluation Of Modern Dosimetry Techniques Near Low- And High-Density Heterogeneities, Eyad A. Alhakeem, Sami Alshaikh, Anatoly B. Rosenfeld, Sergei F. Zavgorodni

Faculty of Engineering and Information Sciences - Papers: Part A

The purpose of this study is to compare performance of several dosimetric methods in heterogeneous phantoms irradiated by 6 and 18 MV beams. Monte Carlo (MC) calculations were used, along with two versions of Acuros XB, anisotropic analytical algorithm (AAA), EBT2 film, and MOSkin dosimeters. Percent depth doses (PDD) were calculated and measured in three heterogeneous phantoms. The first two phantoms were a 30 x 30 x 30 cm3 solid-water slab that had an air-gap of 20x 2.5 x 2.35 cm3. The third phantom consisted of 30 x 30 x 5 cm3 solid water slabs, two 30 x 30 x …


Effect Of Pre-Quenching Process On Microstructure And Mechanical Properties In A Nb-Microalloyed Low Carbon Q-P Steel, Jun Zhang, Hua Ding, Jingwei Zhao Jan 2015

Effect Of Pre-Quenching Process On Microstructure And Mechanical Properties In A Nb-Microalloyed Low Carbon Q-P Steel, Jun Zhang, Hua Ding, Jingwei Zhao

Faculty of Engineering and Information Sciences - Papers: Part A

A refined microstructure consisting of martensite and retained austenite at room temperature has been produced in a Nb-microalloyed low carbon Si-Mn steel by a novel heat-treatment, pre-quenching prior to quenching and partitioning processes (Q&Q-P). The results showed that compared with the conventional quenching and partitioning steel the mechanical properties of steel obtained by the novel treatment have been significantly improved, with a good combination of ultimate tensile strength (1000MPa) and total elongation (above 30%). Meanwhile, the volume fraction of retained austenite has been increased. It was found that the improvement of mechanical properties was mainly attributed to the enhanced TRIP …


High Rate Serially Concatenated Codes With Low Error Floors, Bo Liu, Sheng Tong, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu Jan 2015

High Rate Serially Concatenated Codes With Low Error Floors, Bo Liu, Sheng Tong, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu

Faculty of Engineering and Information Sciences - Papers: Part A

Serial concatenation of Hamming codes and an accumulator has been shown to achieve near capacity performance at high code rates. However, these codes usually exhibit poor error floor performance due to their small minimum distances. To overcome this weakness, we propose to replace the outer Hamming codes by product codes constructed from Hamming codes and single-parity-check codes. In this way, the minimum distance of the outer code can be doubled, which is expected to increase the minimum distance of the serially concatenated code and thus to improve error floor performance. Three-dimensional EXIT chart is used for their convergence analysis and …


An Application Of Mathematical Morphology Operators As Features Extraction Method For Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Dwi B. Wibowo, Mochammad Ariyanto, Joga D. Setiawan Jan 2015

An Application Of Mathematical Morphology Operators As Features Extraction Method For Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Dwi B. Wibowo, Mochammad Ariyanto, Joga D. Setiawan

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new application of mathematical morphology (MM) operators for low speed slew bearing condition monitoring. The MM operators were used as a signal processing step and feature extraction method for bearing vibration signals. Four basic MM operators; erosion, dilation, closing and opening, were studied. This paper also investigates another potential MM operator, namely gradient operator. Two common time domain features in bearing condition monitoring, namely root mean square (RMS) and kurtosis, were extracted from the processed signal. The study shows that the changes in bearing condition can be clearly detected from the extracted features (RMS and kurtosis) …


Are Low-Skill Public Sector Workers Really Overpaid? A Quasi-Differenced Panel Data Analysis, Peter Siminski Feb 2014

Are Low-Skill Public Sector Workers Really Overpaid? A Quasi-Differenced Panel Data Analysis, Peter Siminski

Peter Siminski

Public–private sectoral wage differentials have been studied extensively using quantile regression techniques. These typically find large public sector premiums at the bottom of the wage distribution. This may imply that low skill workers are ‘overpaid’, prompting concerns over efficiency. We note several other potential explanations for this result and explicitly test whether the premium varies with skill, using Australian data. We use a quasi-differenced Generalized Method of Moments (GMM) panel data model which has not been previously applied to this topic, internationally. Unlike other available methods, this technique identifies sectoral differences in returns to unobserved skill. It also facilitates a …